why does my E-mail display a use of 90% of my limit where my inbox content does not have 10% of the mail capacity

why does my E-mail display a use of 90% of my limit where my inbox content does not have 10% of the mail capacity

Dear Sir,

for some reason my Mail seems to be blocked with 5GB of data, however I do not have 5GB of data in my Inbox.

I have only 100 ordinary E-mails in my inbox with lest than 100 MB of capacity.

please explain the issue, and what can I do in order to reflect the correct capacity, and avoid Zoho for locking my account?

Appreciate your help, and awaiting for your prompt response,

Yariv